Chemical-sensing techniques that employ surface-enhanced luminescence, such as surface-enhanced Raman spectroscopy (SERS), have emerged as leading-edge techniques for the analysis of the structure of complex organic molecules, in particular, biomolecules and even biological cells, viruses and their macromolecular components. For example, in SERS, scientists engaged in the application of Raman spectroscopy have found that it is possible to enhance the intensity of a Raman spectrum of a molecule. For example, by decorating a surface, upon which a molecule is later adsorbed, with a thin layer of a metal, surface plasmons are generated that have frequencies in the range of electromagnetic radiation emitted by such a molecule that enhance the intensity of the Raman spectrum of the molecule.
In addition, spectroscopists utilizing spectroscopic techniques for the analysis of molecular structures have a continuing interest in improving the sensitivity of their spectroscopic techniques. Not only is increased sensitivity useful for reducing the time of analysis, but also increased sensitivity can provide previously unachievable results. For example, increased sensitivity is directly related to lower detectability limits for previously undetected molecular constituents. Thus, scientists engaged in the application of surface-enhanced luminescence techniques are motivated to increase the sensitivity of surface-enhanced luminescence techniques, for example, SERS, for the detection of molecules and the spectral signatures of moieties in these molecules.
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